Oval black spinel cabochon with intense vitreous luster and absolute opacity. Nominal dimensions of 13×10 mm. Stock selected from a wholesale lapidary market.
Piece Details
| Mineral |
Black Spinel (MgAl₂O₄) |
| Dimensions |
13×10 mm (tolerance ±0.5 mm) |
| Shape and Back |
Oval, flat back |
| Finish |
Mirror polish |
| Hardness |
8 Mohs — suitable for rings and pendants for daily wear; we recommend a closed bezel setting |
| Origin |
Material acquired from a wholesale lapidary market (Myanmar / Sri Lanka) |
| Treatment |
No treatment |
| Piece Type |
Available in bulk |
This particular piece
Natural black spinel features a jet-black opacity with a vitreous luster reminiscent of molten glass. Unlike dyed onyx, the black color of spinel is structural: it comes from the concentration of iron and chromium in the cubic crystal lattice, not from applied pigments.
The 13×10 mm proportion fits size 17-19 ring mounts or pendant settings. The oval format allows for a closed bezel with minimal metal, reducing the total weight of the finished piece.
What setting it works for
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Bezel setting (925 silver or other precious metals) — the 8 Mohs hardness withstands the crimping of the bezel without chipping; the contrast with oxidized silver is particularly striking.
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Statement rings / Pendants with silver settings — the 13×10 mm oval format makes a statement without being overly heavy.
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Wire wrap — the flat back and regular perimeter facilitate a clean wrap.
Black spinel in lapidary tradition
For centuries, spinel was confused with ruby and sapphire. The so-called "Black Prince's Ruby" that crowns the British Crown Jewels is, in fact, a red spinel. Medieval Persian and Indian lapidaries valued it for its superior vitreous luster and stable color under any light. In crystal tradition, black spinel is associated with protection and mental clarity — the stone that absorbs external noise and allows one to focus on the essential.
The symbolic properties attributed to minerals belong to cultural and historical traditions. They are shared for educational purposes, not as medical advice or a substitute for professional care.
How to recognize genuine black spinel
Natural spinel has a brilliant vitreous luster that dyed onyx does not achieve. Under magnification, spinel may show small mineral inclusions; dyed onyx usually presents micropores and a perfectly uniform color. The 8 Mohs hardness scratches quartz (7) easily, while black glass (Mohs 5.5) is scratched by quartz.
Frequently Asked Questions
Is it natural or dyed black spinel?
No detectable treatment. The black color is structural, a result of the mineralogical composition. Statement based on lapidary observation; the piece does not include formal gemological certification.
What setting is it most suitable for?
Bezel setting in 925 silver or other precious metals. The 8 Mohs hardness allows for daily wear. It also works in wire wrap with silver or copper.
Are the dimensions exact?
The measurements are nominal 13×10 mm. As it is lapidary stock not industrially calibrated, there may be a variation of ±0.5 mm between pieces.
What makes this spinel unique?
The structural black produces a more stable and brilliant luster than dyed onyx. The cubic crystal lattice generates a specular finish that does not vary with time or light.
Can it be worn in daily rings?
Yes. The 8 Mohs hardness makes it one of the most resistant stones for everyday jewelry. We recommend a closed bezel setting to protect the edges.
How to care for it?
Resistant to water and most common chemical agents. Avoid sudden impacts. More information on jewelry care.
See also: cabochon collection · faceted gemstones.
